The present invention relates to vacuum cleaners, and, particular, to a vacuum cleaner having two blowers.
In the past, upright vacuum cleaners for cleaning carpets have generally had a single blower near the air inlet, which pulled air and dirt into the vacuum cleaner and pushed the air through a vacuum cleaner bag, which served as an air filter. The dirt was left in the bag, and the air left the vacuum cleaner through some sort of outlet, such as the pores in a cloth enclosure bag. Cannister-type vacuums generally have a one or two stage blower pulling air through a filter.
Those types of vacuum cleaners were not very energy efficient, but they worked well, as long as they were operated from the household electrical power. However, when people attempted to operate a typical upright vacuum cleaner from a battery, it failed to produce enough air flow for proper suction, and it failed to pick up the dirt in the carpets. Both in the interest of saving energy and in the interest of taking advantage of the convenience of battery operation, the problem to be solved by the present invention was how to make a vacuum cleaner that worked as well as the prior art vacuum cleaners without using as much power.